[PATCH 6/9] net/sfc: avoid speed reset when setting FEC in started state

[Ivan Malov <ivan.malov@arknetworks.am>]

The 'current' mask of PHY capabilities in libefx indicates autonegotiation
regardless of whether the last invocation of 'efx_phy_adv_cap_set' enabled
or disabled it. The port start code is aware of this and pays attention to
preserve the existing setting when making 'efx_phy_adv_cap_set' invocation.

FEC set method uses the 'current' mask as a base for the new value and may
thus reset fixed speed to autonegotiated. Fix it to keep the speed setting.

Fixes: 5efa8fc1cfc0 ("net/sfc: support FEC feature")
Cc: stable@dpdk.org

Signed-off-by: Ivan Malov <ivan.malov@arknetworks.am>
Reviewed-by: Andy Moreton <andy.moreton@amd.com>
---
 drivers/net/sfc/sfc_ethdev.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index 99141bdda5..6d2349a999 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -2857,8 +2857,13 @@ sfc_fec_set(struct rte_eth_dev *dev, uint32_t fec_capa)
 	if (sa->state == SFC_ETHDEV_STARTED) {
 		efx_phy_adv_cap_get(sa->nic, EFX_PHY_CAP_CURRENT,
 				    &updated_caps);
-		updated_caps = updated_caps & ~EFX_PHY_CAP_FEC_MASK;
-		updated_caps |= efx_fec_caps;
+
+		/* Keep pause capabilities set by efx_mac_fcntl_set(). */
+		updated_caps = (updated_caps & EFX_PHY_CAP_PAUSE_MASK) |
+			       (port->phy_adv_cap & ~EFX_PHY_CAP_PAUSE_MASK);
+
+		updated_caps = (updated_caps & ~EFX_PHY_CAP_FEC_MASK) |
+			       (efx_fec_caps & EFX_PHY_CAP_FEC_MASK);
 
 		rc = efx_phy_adv_cap_set(sa->nic, updated_caps);
 		if (rc != 0)
-- 
2.47.3